To build off of this, the best thing an average (American) Jane/Joe can do is pile money into their 401k and when they switch jobs move the money from the 401k into a (Roth)IRA
Individual investors can basically never beat the market no matter how smart they are nor how many hours the pile into their research. Best to just pile the money into diversified fund containing a solid mix of stock indices and bonds. If you want to be extra smart, deposit more while the market is down/super unstable so you can ride the wave up when the market grows again.
There's generally advise to not invest if you have high interest debt and to instead pile your spare cash into paying that down. My personal opinion is that if you're someone who has a consistent revolving balance of debt just start shoving spare cash into a retirement account (and don't touch it!) because that can at least build up while you slowly get your debts under control and while maybe you won't pay off your debt as quickly, at least you have something already saved and compounding 10 years from now once everything is stabilized and paid off